Vendor Surveillance at Bilbao Forges, Foundries and Heavy Fabricators

Where quality is decided on a forging or casting order

On a welded vessel, most of the inspectable risk is created in the weld shop. On a forging or a casting it is created upstream, in decisions the purchaser never sees: the scrap mix and ladle chemistry, whether the ingot was bottom-poured, how much of the hot top was cropped, the reduction achieved through the press, the soak time at austenitising temperature, and the severity and delay of the quench. By the time an inspector arrives to witness ultrasonic examination on a rough-turned shaft, the outcome was determined weeks earlier by people who were not being watched.

That changes what surveillance has to look like on this kind of order. The useful hold points are early and metallurgical: approval of the manufacturing procedure specification, witness of the qualification heat where one is required, presence at the heat treatment charge, and control over when volumetric examination happens relative to machining. Attending only the final NDT is attending the autopsy — the information arrives after every decision that could have changed the result has already been taken.

It also changes who has to attend. Reading an EN 10228-3 report against a quality class, judging whether an attenuation problem in a duplex forging is a grain-size issue or a technique issue, and deciding whether a cluster of indications in a casting is shrinkage porosity or cracking all require someone with method-level authority who can defend the call at the time it is made. That is a Level III consulting judgement, not a clerical check against a table.

The ITP for a forging or casting order

A vessel ITP is organised around welding. A forging or casting ITP has to be organised around the melt-to-delivery route, and it needs lines that a fabrication ITP simply does not carry: chemistry approval per heat, ingot and cropping records, forging ratio or casting method approval, heat treatment procedure and furnace chart review, test coupon location and orientation, mechanical testing witness, volumetric and surface NDT at a defined machining stage, repair authorisation, dimensional verification, and marking and traceability.

Two of those lines matter more than the rest combined. The first is the stage at which volumetric NDT is performed relative to machining. The second is whether the foundry or forge may repair a discontinuity before the purchaser has seen the original result. Leaving either to the supplier's discretion converts a surveillance contract into a paperwork exercise, because both decisions determine what the inspector is ever allowed to see.

The ITP should also state what the purchaser intends to do with the records, not merely who signs them. Where the components go into an operating asset with a long inspection life — a pressure-containing casting, a wind turbine main shaft, a heavy valve body — the as-manufactured NDT result is the baseline that every future in-service examination will be compared against, and it needs to survive the project handover rather than ending its life in a delivery folder.

Volumetric acceptance: the standard is not the acceptance criterion

The single most common commercial failure on this kind of order is a purchase order that names a standard and no level. EN 10228-3 defines quality classes for ultrasonic examination of ferritic steel forgings; EN 10228-4 does the same for austenitic and austenitic-ferritic grades; EN 12680 defines severity levels for castings by zone; ASTM A609 works through quality levels; and ASTM E446, E186 and E280 supply reference radiographs by severity and category across three section thickness ranges. In every one of those documents the standard defines how to examine and how to classify what is found, and the purchase order defines what is acceptable.

When the level is missing, the supplier prices and produces against the most permissive interpretation available while the purchaser assumes the most severe. The disagreement surfaces at final inspection, with a finished component sitting in the bay and a delivery date already committed to an end client. It is entirely avoidable at PO stage and it takes one line of text. Reviewing the technical section of the order before it is placed is the cheapest inspection activity there is.

The second trap is coverage. Complex forgings and castings have geometry that cannot be scanned from every face, and the standards permit examination to be limited by accessible surfaces. A report that quietly reduces scanning coverage without saying so is technically compliant and practically useless. Independent validation of inspection reports against the technique sheet — probe frequency and size, reference block, DAC or DGS basis, scan plan, and coverage actually achieved — is where those reports get caught, usually before the component ships rather than after it fails.

Heat treatment and mechanical testing: what has to be witnessed

Mechanical properties are certified from test coupons, and the certificate is only as honest as the relationship between the coupon and the part. The coupon must be integral or attached where the specification requires it, taken from the location and orientation specified, and heat-treated with the production charge rather than separately. A coupon treated on its own in a small laboratory furnace, quenched with an agitation and a section size nothing like the part, is the oldest shortcut in the business and it produces a certificate that is true about the coupon and false about the forging.

At the furnace, the items to verify are calibration and temperature survey status, thermocouple number and placement, the charge map, ramp rates, soak temperature and time at temperature, and then the quench: delay from furnace door to tank, quenchant temperature, and agitation. A duplex or low-temperature carbon steel component that spent an extra ninety seconds in air on the way to the tank will still pass a hardness check and then fail Charpy testing at the specified temperature, and by that point the only remedy is re-heat-treatment with all the dimensional and NDT consequences that follow.

Charpy impact testing is where the arguments happen: the test temperature, specimen size and the reduction factors applied to sub-size specimens, the retest rules, and whether the reported set average and individual minimum both satisfy the requirement rather than just the average. Where the supplier's own laboratory performs the testing, its scope of accreditation is worth reading rather than assuming. Personnel performing NDT should hold current certification to EN ISO 9712 or SNT-TC-1A at the applicable level in the applicable method, and where a supplier's certification structure is thin, formal NDT training and certification is a faster fix than a season of argument over report quality.

Hold points suppliers ask to waive on this kind of order

Three requests recur, and they arrive politely. Release the heat treatment charge before the purchaser's inspector arrives, because the furnace is booked and the next slot is a week away. Machine to final size before ultrasonic examination, because the schedule is tight and machining is already set up. Repair a small casting indication now and present the repaired result, because the foundry is confident it is minor and re-examination will be clean.

All three are cheap to grant and expensive to have granted. Missing the heat treatment charge means the certificate can never be corroborated against what actually happened in the furnace. Machining before ultrasonic examination removes exactly the material that would have allowed an indication to be excavated and the component saved. And a repair the purchaser never saw in its original state cannot be assessed for whether the underlying cause — a feeding problem, a mould defect, a pattern that repeats across the heat — is going to reappear in the next twelve castings on the same order.

The disciplined answer is not to refuse everything, because a surveillance regime that never flexes gets worked around rather than complied with. It is to write the waiver down, name the person granting it, state what compensating verification will replace the missed observation, and report the pattern in the monthly summary. A supplier requesting the same waiver on every item in a campaign is describing its own production planning, and that description belongs in the next tender evaluation.

Expediting a forging or casting order

Forging and casting programmes fail in predictable places. Melt slots are shared across a plant's whole order book and slip whenever a larger order arrives. Press availability is finite and is allocated by the works rather than by the customer. Heat treatment furnaces are a bottleneck at every plant of this type. Laboratory turnaround for mechanical testing is routinely underestimated by both parties to the contract. And final machining is subcontracted far more often than purchasers realise, which puts a critical path operation somewhere the purchase order may not reach.

Effective expediting on this kind of order therefore tracks a short list of dated binary events rather than a percentage complete: melt date, ingot available, forged, heat treated, rough machined, NDT complete, test results issued, final machined, certified, released. Each one is either done or not done, and each one is verifiable on the shop floor by an inspector who is already in the building for other reasons. Percentage complete on a forging order is a negotiation; a heat treatment charge sheet with yesterday's date on it is a fact.

Where the components are large and dimensionally critical — turbine casings, large valve bodies, hub castings, machined interfaces on weldments — dimensional verification becomes a schedule risk in its own right. 3D laser scanning against the model produces an as-built record in hours rather than days on a marking-out table, and gives the purchaser something defensible if a fit-up dispute follows later at the assembly site, when the component is thousands of kilometres from the works that made it.

The release dossier for a forged or cast component

The package is narrower than a vessel dossier but far less forgiving, because the component's entire history is metallurgical and none of it can be re-created after the fact. Expect heat chemistry with both ladle and product analysis, the melt and ingot record, forging or casting method records, the heat treatment procedure together with the furnace chart for the actual charge, mechanical test certificates traceable to coupon location and orientation, hardness survey results, full NDT reports with technique sheets and operator certification, the repair map and repair welding records where repairs were made, the dimensional report, the marking and traceability record, and the EN 10204 certificate at the ordered level with countersignature where 3.2 was specified.

The furnace chart is the document most often accepted without being read, and it is the one that rewards reading. A trace with a thermocouple flat-lining part way through the soak, a ramp rate outside the approved procedure, a soak period measured from the wrong reference point, or a charge identification that does not correspond to the part number in front of you — all of these are findings available to anyone who opens the file rather than initialling the index.

Traceability is the other weak point, and it is mundane rather than technical. Hard stamping, low-stress stamping, colour coding and the transfer of heat numbers at cutting are where identity is lost. When a component is cut from a larger forging or a multiple casting, the transfer of identification must be witnessed or the traceability chain is broken at precisely the point where it carries the most value.

Continuity of personnel across a campaign

Atlantis inspection teams mobilise from Houston and Hyderabad and remain deployed with the supplier for the contract term. On metallurgical orders that continuity is worth more than on almost any other kind of inspection work, because so many of the decisions are comparative rather than absolute. Whether this heat's inclusion pattern is normal for this works. Whether this furnace always runs cool near the door. Whether this quench tank is properly agitated on the night shift. Those judgements are formed over months of attendance and they are lost completely the moment the inspector changes.

Continuity also produces a consistent record, which matters when the dossier is read by someone else later. Sixty castings assessed by one person against one interpretation of a severity level is a defensible package. The same sixty assessed by four inspectors across four rotations is a package full of internal contradictions, and the purchaser's own client will find them faster than the purchaser does.

Coverage flexes with the programme rather than being fixed: resident presence during melt, heat treatment and NDT campaigns, part-time during machining and certification, and monthly reporting against days consumed, ITP lines closed, non-conformances open and closed, and schedule status against the baseline. On a multi-supplier package in the same area, one deployed inspector can carry a small portfolio of works, which is usually the most economical way to buy this coverage.

Procurement traps in this supply chain

Manufacturer qualification versus order qualification. A supplier holding a NORSOK M-650 Qualification Test Record, an approval from one end user, or a qualification earned on a previous project will offer it as evidence of capability for the order in front of you. Read what it actually covers — product form, thickness range, grade, manufacturing route, heat treatment equipment, and the specific works that performed the work. Qualifications are routinely narrower than the orders they are offered against, and the gap only becomes visible when someone reads the certificate rather than noting its existence.

Sub-contracted operations. Machining, heat treatment and NDT are frequently performed outside the main supplier's premises, sometimes at considerable distance. Inspection rights and access have to follow the work rather than the contract signature, and the ITP must name where each activity physically happens. An access clause that stops at the main gate is worth nothing when the furnace that determines the mechanical properties is thirty kilometres away at a third party.

And rolled-over specifications. Heavy component orders are often repeats of previous ones, with the specification revision copied unchanged into the PO text while the client's engineering standard has moved on two revisions. Cite the specification number and revision explicitly, and reconcile it at the pre-inspection meeting where the production team can hear it. If you want a supplier's qualification records, ITP and technical order package reviewed before the order is placed, request a consultation and we will mark up what needs to change while changing it is still free.

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